1
|
Mani BK, Osborne-Lawrence S, Vijayaraghavan P, Hepler C, Zigman JM. β1-Adrenergic receptor deficiency in ghrelin-expressing cells causes hypoglycemia in susceptible individuals. J Clin Invest 2016; 126:3467-78. [PMID: 27548523 DOI: 10.1172/jci86270] [Citation(s) in RCA: 45] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/30/2015] [Accepted: 07/07/2016] [Indexed: 01/06/2023] Open
Abstract
Ghrelin is an orexigenic gastric peptide hormone secreted when caloric intake is limited. Ghrelin also regulates blood glucose, as emphasized by the hypoglycemia that is induced by caloric restriction in mouse models of deficient ghrelin signaling. Here, we hypothesized that activation of β1-adrenergic receptors (β1ARs) localized to ghrelin cells is required for caloric restriction-associated ghrelin release and the ensuing protective glucoregulatory response. In mice lacking the β1AR specifically in ghrelin-expressing cells, ghrelin secretion was markedly blunted, resulting in profound hypoglycemia and prevalent mortality upon severe caloric restriction. Replacement of ghrelin blocked the effects of caloric restriction in β1AR-deficient mice. We also determined that treating calorically restricted juvenile WT mice with beta blockers led to reduced plasma ghrelin and hypoglycemia, the latter of which is similar to the life-threatening, fasting-induced hypoglycemia observed in infants treated with beta blockers. These findings highlight the critical functions of ghrelin in preventing hypoglycemia and promoting survival during severe caloric restriction and the requirement for ghrelin cell-expressed β1ARs in these processes. Moreover, these results indicate a potential role for ghrelin in mediating beta blocker-associated hypoglycemia in susceptible individuals, such as young children.
Collapse
|
2
|
Church JE, Trieu J, Sheorey R, Chee AYM, Naim T, Baum DM, Ryall JG, Gregorevic P, Lynch GS. Functional β-adrenoceptors are important for early muscle regeneration in mice through effects on myoblast proliferation and differentiation. PLoS One 2014; 9:e101379. [PMID: 25000590 PMCID: PMC4084885 DOI: 10.1371/journal.pone.0101379] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/28/2014] [Accepted: 06/05/2014] [Indexed: 12/25/2022] Open
Abstract
Muscles can be injured in different ways and the trauma and subsequent loss of function and physical capacity can impact significantly on the lives of patients through physical impairments and compromised quality of life. The relative success of muscle repair after injury will largely determine the extent of functional recovery. Unfortunately, regenerative processes are often slow and incomplete, and so developing novel strategies to enhance muscle regeneration is important. While the capacity to enhance muscle repair by stimulating β2-adrenoceptors (β-ARs) using β2-AR agonists (β2-agonists) has been demonstrated previously, the exact role β-ARs play in regulating the regenerative process remains unclear. To investigate β-AR-mediated signaling in muscle regeneration after myotoxic damage, we examined the regenerative capacity of tibialis anterior and extensor digitorum longus muscles from mice lacking either β1-AR (β1-KO) and/or β2-ARs (β2-KO), testing the hypothesis that muscles from mice lacking the β2-AR would exhibit impaired functional regeneration after damage compared with muscles from β1-KO or β1/β2-AR null (β1/β2-KO) KO mice. At 7 days post-injury, regenerating muscles from β1/β2-KO mice produced less force than those of controls but muscles from β1-KO or β2-KO mice did not exhibit any delay in functional restoration. Compared with controls, β1/β2-KO mice exhibited an enhanced inflammatory response to injury, which delayed early muscle regeneration, but an enhanced myoblast proliferation later during regeneration ensured a similar functional recovery (to controls) by 14 days post-injury. This apparent redundancy in the β-AR signaling pathway was unexpected and may have important implications for manipulating β-AR signaling to improve the rate, extent and efficacy of muscle regeneration to enhance functional recovery after injury.
Collapse
MESH Headings
- Animals
- Cell Differentiation
- Cell Proliferation
- Gene Knockout Techniques
- Mice
- Muscle Strength
- Muscle, Skeletal/anatomy & histology
- Muscle, Skeletal/cytology
- Muscle, Skeletal/physiology
- Myoblasts/cytology
- Organ Size
- Receptors, Adrenergic, beta-1/deficiency
- Receptors, Adrenergic, beta-1/genetics
- Receptors, Adrenergic, beta-1/metabolism
- Receptors, Adrenergic, beta-2/deficiency
- Receptors, Adrenergic, beta-2/genetics
- Receptors, Adrenergic, beta-2/metabolism
- Regeneration
Collapse
Affiliation(s)
- Jarrod E. Church
- Basic and Clinical Myology Laboratory, Department of Physiology, The University of Melbourne, Victoria, Australia
| | - Jennifer Trieu
- Basic and Clinical Myology Laboratory, Department of Physiology, The University of Melbourne, Victoria, Australia
| | - Radhika Sheorey
- Basic and Clinical Myology Laboratory, Department of Physiology, The University of Melbourne, Victoria, Australia
| | - Annabel Y. -M. Chee
- Basic and Clinical Myology Laboratory, Department of Physiology, The University of Melbourne, Victoria, Australia
| | - Timur Naim
- Basic and Clinical Myology Laboratory, Department of Physiology, The University of Melbourne, Victoria, Australia
| | - Dale M. Baum
- Basic and Clinical Myology Laboratory, Department of Physiology, The University of Melbourne, Victoria, Australia
| | - James G. Ryall
- Basic and Clinical Myology Laboratory, Department of Physiology, The University of Melbourne, Victoria, Australia
| | - Paul Gregorevic
- Laboratory for Muscle Research & Therapeutics Development, Baker IDI Heart and Diabetes Institute, Victoria, Australia
| | - Gordon S. Lynch
- Basic and Clinical Myology Laboratory, Department of Physiology, The University of Melbourne, Victoria, Australia
- * E-mail:
| |
Collapse
|
3
|
Chiarella SE, Soberanes S, Urich D, Morales-Nebreda L, Nigdelioglu R, Green D, Young JB, Gonzalez A, Rosario C, Misharin AV, Ghio AJ, Wunderink RG, Donnelly HK, Radigan KA, Perlman H, Chandel NS, Budinger GRS, Mutlu GM. β₂-Adrenergic agonists augment air pollution-induced IL-6 release and thrombosis. J Clin Invest 2014; 124:2935-46. [PMID: 24865431 DOI: 10.1172/jci75157] [Citation(s) in RCA: 97] [Impact Index Per Article: 9.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/16/2014] [Accepted: 04/03/2014] [Indexed: 01/05/2023] Open
Abstract
Acute exposure to particulate matter (PM) air pollution causes thrombotic cardiovascular events, leading to increased mortality rates; however, the link between PM and cardiovascular dysfunction is not completely understood. We have previously shown that the release of IL-6 from alveolar macrophages is required for a prothrombotic state and acceleration of thrombosis following exposure to PM. Here, we determined that PM exposure results in the systemic release of catecholamines, which engage the β2-adrenergic receptor (β2AR) on murine alveolar macrophages and augment the release of IL-6. In mice, β2AR signaling promoted the development of a prothrombotic state that was sufficient to accelerate arterial thrombosis. In primary human alveolar macrophages, administration of a β2AR agonist augmented IL-6 release, while the addition of a beta blocker inhibited PM-induced IL-6 release. Genetic loss or pharmacologic inhibition of the β2AR on murine alveolar macrophages attenuated PM-induced IL-6 release and prothrombotic state. Furthermore, exogenous β2AR agonist therapy further augmented these responses in alveolar macrophages through generation of mitochondrial ROS and subsequent increase of adenylyl cyclase activity. Together, these results link the activation of the sympathetic nervous system by β2AR signaling with metabolism, lung inflammation, and an enhanced susceptibility to thrombotic cardiovascular events.
Collapse
MESH Headings
- Adenylyl Cyclases/biosynthesis
- Adrenergic beta-2 Receptor Agonists/administration & dosage
- Adrenergic beta-2 Receptor Agonists/adverse effects
- Animals
- Antithrombin III/biosynthesis
- Bronchoalveolar Lavage Fluid/chemistry
- Catecholamines/biosynthesis
- Colforsin/administration & dosage
- Humans
- Interleukin-6/biosynthesis
- Macrophages, Alveolar/drug effects
- Macrophages, Alveolar/physiology
- Male
- Mice
- Mice, Knockout
- Particulate Matter/administration & dosage
- Particulate Matter/adverse effects
- Peptide Hydrolases/biosynthesis
- Propranolol/administration & dosage
- Propranolol/adverse effects
- Reactive Oxygen Species/metabolism
- Receptors, Adrenergic, beta/deficiency
- Receptors, Adrenergic, beta/genetics
- Receptors, Adrenergic, beta-1/deficiency
- Receptors, Adrenergic, beta-1/genetics
- Thrombosis/etiology
Collapse
|
4
|
Zieziulewicz TJ, Mondal TK, Gao D, Lawrence DA. Stress-induced effects, which inhibit host defenses, alter leukocyte trafficking. Cell Stress Chaperones 2013; 18:279-91. [PMID: 23111563 PMCID: PMC3631090 DOI: 10.1007/s12192-012-0380-0] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/01/2012] [Revised: 10/08/2012] [Accepted: 10/09/2012] [Indexed: 12/24/2022] Open
Abstract
Acute cold restraint stress (ACRS) has been reported to suppress host defenses against Listeria monocytogenes, and this suppression was mediated by beta1-adrenoceptors (β1-ARs). Although ACRS appears to inhibit mainly early innate immune defenses, interference with leukocyte chemotaxis and the involvement of β1-AR (or β2-AR) signaling had not been assessed. Thus, the link between sympathetic nerve stimulation, release of neurotransmitters, and changes in blood leukocyte profiles, including oxidative changes, following ACRS was evaluated. The numbers of leukocyte subsets in the blood were differentially affected by β1-ARs and β2-ARs following ACRS; CD3(+) (CD4 and CD8) T-cells were shown to be decreased following ACRS, and the T cell lymphopenia was mediated mainly through a β2-AR mechanism, while the decrease in CD19(+) B-cells was influenced through both β1- and β2-ARs, as assessed by pharmacological and genetic manipulations. In contrast to the ACRS-induced loss of circulating lymphocytes, the number of circulating neutrophils was increased (i.e., neutrophilia), and this neutrophilia was mediated through β1-ARs. The increase in circulating neutrophils was not due to an increase in serum chemokines promoting neutrophil emigration from the bone marrow; rather it was due to neutrophil release from the bone marrow through activation of a β1-AR pathway. There was no loss of glutathione in any of the leukocyte subsets suggesting that there was minimal oxidative stress; however, there was early production of nitric oxide and generation of some protein radicals. Premature egress of neutrophils from bone marrow is suggested to be due to norepinephrine induction of nitric oxide, which affects the early release of neutrophils from bone marrow and lessens host defenses.
Collapse
MESH Headings
- Animals
- Bone Marrow/drug effects
- Bone Marrow/metabolism
- Chemokine CXCL12/pharmacology
- Chemotactic Factors/blood
- Chemotaxis, Leukocyte/drug effects
- Chemotaxis, Leukocyte/immunology
- Cold Temperature
- Gene Expression Regulation/drug effects
- Glutathione/metabolism
- Leukocytes/drug effects
- Leukocytes/metabolism
- Leukocytes/pathology
- Lymphocytes/drug effects
- Lymphocytes/metabolism
- Lymphopenia/blood
- Lymphopenia/immunology
- Lymphopenia/pathology
- Male
- Mice
- Mice, Inbred BALB C
- Mice, Knockout
- Neutrophils/drug effects
- Neutrophils/metabolism
- Nitric Oxide/biosynthesis
- Oxidative Stress/drug effects
- RNA, Messenger/genetics
- RNA, Messenger/metabolism
- Receptors, Adrenergic, beta-1/deficiency
- Receptors, Adrenergic, beta-1/genetics
- Receptors, Adrenergic, beta-1/metabolism
- Receptors, Adrenergic, beta-2/metabolism
- Restraint, Physical
- Stress, Physiological/drug effects
- Stress, Physiological/immunology
Collapse
Affiliation(s)
- Thomas J. Zieziulewicz
- />Laboratory of Immunology, Wadsworth Center, New York State Department of Health, Albany, NY 12208 USA
| | - Tapan K. Mondal
- />Laboratory of Immunology, Wadsworth Center, New York State Department of Health, Albany, NY 12208 USA
| | - Donghong Gao
- />Laboratory of Immunology, Wadsworth Center, New York State Department of Health, Albany, NY 12208 USA
| | - David A. Lawrence
- />Laboratory of Immunology, Wadsworth Center, New York State Department of Health, Albany, NY 12208 USA
- />Laboratory of Immunology, David Axelrod Institute, Wadsworth Center, New York State Department of Health, 120 New Scotland Avenue, Albany, NY 12208-3425 USA
| |
Collapse
|
5
|
Zhang W, Yano N, Deng M, Mao Q, Shaw SK, Tseng YT. β-Adrenergic receptor-PI3K signaling crosstalk in mouse heart: elucidation of immediate downstream signaling cascades. PLoS One 2011; 6:e26581. [PMID: 22028912 PMCID: PMC3197531 DOI: 10.1371/journal.pone.0026581] [Citation(s) in RCA: 47] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/19/2011] [Accepted: 09/29/2011] [Indexed: 01/21/2023] Open
Abstract
Sustained β-adrenergic receptors (βAR) activation leads to cardiac hypertrophy and prevents left ventricular (LV) atrophy during LV unloading. The immediate signaling pathways downstream from βAR stimulation, however, have not been well investigated. The current study was to examine the early cardiac signaling mechanism(s) following βAR stimulation. In adult C57BL/6 mice, acute βAR stimulation induced significant increases in PI3K activity and activation of Akt and ERK1/2 in the heart, but not in lungs or livers. In contrast, the same treatment did not elicit these changes in β1/β2AR double knockout mice. We further showed the specificity of β2AR in this crosstalk as treatment with formoterol, a β2AR-selective agonist, but not dobutamine, a predominantly β1AR agonist, activated cardiac Akt and ERK1/2. Acute βAR stimulation also significantly increased the phosphorylation of mTOR (the mammalian target of rapamycin), P70S6K, ribosomal protein S6, GSK-3α/β (glycogen synthase kinase-3α/β), and FOXO1/3a (the forkhead box family of transcription factors 1 and 3a). Moreover, acute βAR stimulation time-dependently decreased the mRNA levels of the muscle-specific E3 ligases atrogin-1 and muscle ring finger protein-1 (MuRF1) in mouse heart. Our results indicate that acute βAR stimulation in vivo affects multiple cardiac signaling cascades, including the PI3K signaling pathway, ERK1/2, atrogin-1 and MuRF1. These data 1) provide convincing evidence for the crosstalk between βAR and PI3K signaling pathways; 2) confirm the β2AR specificity in this crosstalk in vivo; and 3) identify novel signaling factors involved in cardiac hypertrophy and LV unloading. Understanding of the intricate interplay between β2AR activation and these signaling cascades should provide critical clues to the pathogenesis of cardiac hypertrophy and enable identification of targets for early clinical interaction of cardiac lesions.
Collapse
MESH Headings
- Adrenergic beta-Agonists/pharmacology
- Animals
- Forkhead Transcription Factors/metabolism
- Gene Knockout Techniques
- Glycogen Synthase Kinase 3/metabolism
- Glycogen Synthase Kinase 3 beta
- Male
- Mice
- Mitogen-Activated Protein Kinase 1/metabolism
- Mitogen-Activated Protein Kinase 3/metabolism
- Muscle Proteins/genetics
- Myocardium/cytology
- Myocardium/metabolism
- Organ Specificity
- Phosphatidylinositol 3-Kinases/metabolism
- Phosphorylation/drug effects
- Proto-Oncogene Proteins c-akt/metabolism
- RNA, Messenger/genetics
- RNA, Messenger/metabolism
- Receptors, Adrenergic, beta-1/deficiency
- Receptors, Adrenergic, beta-1/genetics
- Receptors, Adrenergic, beta-1/metabolism
- Receptors, Adrenergic, beta-2/deficiency
- Receptors, Adrenergic, beta-2/genetics
- Receptors, Adrenergic, beta-2/metabolism
- Ribosomal Protein S6 Kinases, 70-kDa/metabolism
- SKP Cullin F-Box Protein Ligases/genetics
- Signal Transduction/drug effects
- TOR Serine-Threonine Kinases/metabolism
- Tripartite Motif Proteins
- Ubiquitin-Protein Ligases/genetics
Collapse
Affiliation(s)
- Weizhi Zhang
- Department of Cardiothoracic Surgery, The Second Xiangya Hospital, Central South University, Changsha, Hunan, China
- Department of Pediatrics, Women and Infants Hospital, The Warren Alpert Medical School of Brown University, Providence, Rhode Island, United States of America
| | - Naohiro Yano
- Department of Pediatrics, Women and Infants Hospital, The Warren Alpert Medical School of Brown University, Providence, Rhode Island, United States of America
| | - Minzi Deng
- Department of Pediatrics, Women and Infants Hospital, The Warren Alpert Medical School of Brown University, Providence, Rhode Island, United States of America
| | - Quanfu Mao
- Department of Pediatrics, Women and Infants Hospital, The Warren Alpert Medical School of Brown University, Providence, Rhode Island, United States of America
| | - Sunil K. Shaw
- Department of Pediatrics, Women and Infants Hospital, The Warren Alpert Medical School of Brown University, Providence, Rhode Island, United States of America
| | - Yi-Tang Tseng
- Department of Pediatrics, Women and Infants Hospital, The Warren Alpert Medical School of Brown University, Providence, Rhode Island, United States of America
- * E-mail:
| |
Collapse
|
6
|
Kim SM, Chen L, Faulhaber-Walter R, Oppermann M, Huang Y, Mizel D, Briggs JP, Schnermann J. Regulation of Renin Secretion and Expression in Mice Deficient in β1- and β2-Adrenergic Receptors. Hypertension 2007; 50:103-9. [PMID: 17515456 DOI: 10.1161/hypertensionaha.107.087577] [Citation(s) in RCA: 48] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
The present experiments were performed in beta1/beta2-adrenergic receptor-deficient mice (beta1/beta2ADR(-/-)) to assess the role of beta-adrenergic receptors in basal and regulated renin expression and release. On a control diet, plasma renin concentration (in ng angiotensin I per mL per hour), determined in tail vein blood, was significantly lower in beta1/beta2ADR(-/-) than in wild-type (WT) mice (222+/-65 versus 1456+/-335; P<0.01). Renin content and mRNA were 77% and 65+/-5% of WT. Plasma aldosterone (in picograms per mL) was also significantly reduced (420+/-36 in beta1/beta2ADR(-/-) versus 692+/-59 in WT). A low-salt diet (0.03%) for 1 week increased plasma renin concentration significantly in both beta1/beta2ADR(-/-) and WT mice (to 733+/-54 and 2789+/-555), whereas a high-salt diet (8%) suppressed it in both genotypes (to 85+/-24 in beta1/beta2ADR(-/-) and to 676+/-213 in WT). The absolute magnitude of salt-induced changes of plasma renin concentration was markedly greater in WT mice. Acute stimulation of renin release by furosemide, quinaprilat, captopril, or candesartan caused significant increases of plasma renin concentration in both beta1/beta2ADR(-/-) and WT mice, but again the absolute changes were greater in WT mice. We conclude that maintenance of normal levels of renin synthesis and release requires tonic beta-adrenergic receptor activation. In the chronic absence of beta-adrenergic receptor input, the size of the releasable renin pool decreases with a concomitant reduction in the magnitude of the plasma renin concentration changes caused by variations of salt intake or acute stimulation with furosemide, angiotensin-converting enzyme, or angiotensin type 1 receptor inhibition, but regulatory responsiveness is nonetheless maintained.
Collapse
Affiliation(s)
- Soo Mi Kim
- National Institute of Digestive and Diabetes and Kidney Diseases, National Institutes of Health, Bethesda, MD 20892, USA
| | | | | | | | | | | | | | | |
Collapse
|
7
|
Ecker PM, Lin CC, Powers J, Kobilka BK, Dubin AM, Bernstein D. Effect of targeted deletions of beta1- and beta2-adrenergic-receptor subtypes on heart rate variability. Am J Physiol Heart Circ Physiol 2005; 290:H192-9. [PMID: 16113068 DOI: 10.1152/ajpheart.00032.2005] [Citation(s) in RCA: 37] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Beta-adrenergic receptors (beta-ARs) play a major role in regulating heart rate (HR) and contractility in the intact cardiovascular system. Three subtypes (beta1, beta2, and beta3) are expressed in heart tissue, and the role of each subtype in regulating cardiac function has previously been determined by using both pharmacological and gene-targeting approaches. However, previous studies have only examined the role of beta-ARs in the macrolevel regulation of HR. We employed three knockout (KO) mouse lines, beta1-KO, beta2-KO, and beta1/beta2 double KO (DL-KO), to examine the role that beta-AR subtypes play in HR variability (HRV) and in the sympathetic and parasympathetic inputs into HR control. Fast Fourier transformation (FFT) in frequency domain methods of ECG spectral analysis was used to resolve HRV into high- and low-frequency (HF and LF) powers. Resting HR (in beats/min) was decreased in beta1-KO [488 (SD 27)] and DL-KO [495 (SD 12)] mice compared with wild-type [WT; 638 (SD 30)] or beta2-KO [656 (SD 51)] (P < 0.0005) mice. Mice lacking beta1-ARs (beta1-KO and DL-KO) had increased HRV (as illustrated by the standard deviation of normal R-R intervals) and increased normalized HF and LF powers compared with mice with intact beta1-ARs (WT and beta2-KO). These results demonstrate the differential role of beta-AR subtypes in regulating autonomic signaling.
Collapse
Affiliation(s)
- Phillip M Ecker
- Dept. of Pediatrics, Stanford University, Stanford, California, USA
| | | | | | | | | | | |
Collapse
|
8
|
Mutlu GM, Dumasius V, Burhop J, McShane PJ, Meng FJ, Welch L, Dumasius A, Mohebahmadi N, Thakuria G, Hardiman K, Matalon S, Hollenberg S, Factor P. Upregulation of alveolar epithelial active Na+ transport is dependent on beta2-adrenergic receptor signaling. Circ Res 2004; 94:1091-100. [PMID: 15016730 DOI: 10.1161/01.res.0000125623.56442.20] [Citation(s) in RCA: 93] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
Abstract
Alveolar epithelial beta-adrenergic receptor (betaAR) activation accelerates active Na+ transport in lung epithelial cells in vitro and speeds alveolar edema resolution in human lung tissue and normal and injured animal lungs. Whether these receptors are essential for alveolar fluid clearance (AFC) or if other mechanisms are sufficient to regulate active transport is unknown. In this study, we report that mice with no beta1- or beta2-adrenergic receptors (beta1AR-/-/beta2AR-/-) have reduced distal lung Na,K-ATPase function and diminished basal and amiloride-sensitive AFC. Total lung water content in these animals was not different from wild-type controls, suggesting that betaAR signaling may not be required for alveolar fluid homeostasis in uninjured lungs. Comparison of isoproterenol-sensitive AFC in mice with beta1- but not beta2-adrenergic receptors to beta1AR-/-/beta2AR-/- mice indicates that the beta2AR mediates the bulk of beta-adrenergic-sensitive alveolar active Na+ transport. To test the necessity of betaAR signaling in acute lung injury, beta1AR-/-/beta2AR-/-, beta1AR+/+/beta2AR-/-, and beta1AR+/+/beta2AR+/+ mice were exposed to 100% oxygen for up to 204 hours. beta1AR-/-/beta2AR-/- and beta1AR+/+/beta2AR-/- mice had more lung water and worse survival from this form of acute lung injury than wild-type controls. Adenoviral-mediated rescue of beta2-adrenergic receptor (beta2AR) function into the alveolar epithelium of beta1AR-/-/beta2AR-/- and beta1AR+/+/beta2AR-/- mice normalized distal lung beta2AR function, alveolar epithelial active Na+ transport, and survival from hyperoxia. These findings indicate that betaAR signaling may not be necessary for basal AFC, and that beta2AR is essential for the adaptive physiological response needed to clear excess fluid from the alveolar airspace of normal and injured lungs.
Collapse
MESH Headings
- Amiloride/pharmacology
- Animals
- Biological Transport, Active/drug effects
- Biological Transport, Active/physiology
- Body Water/metabolism
- Cardiac Output
- Cyclic AMP/metabolism
- Cystic Fibrosis Transmembrane Conductance Regulator/metabolism
- Epithelial Cells/drug effects
- Epithelial Cells/metabolism
- Genotype
- Humans
- Hyperoxia/physiopathology
- Ion Transport/drug effects
- Ion Transport/physiology
- Male
- Mice
- Mice, Inbred C57BL
- Mice, Knockout
- Potassium Channels/metabolism
- Pulmonary Alveoli/drug effects
- Pulmonary Alveoli/injuries
- Pulmonary Alveoli/physiology
- Pulmonary Alveoli/physiopathology
- Receptors, Adrenergic, beta-1/deficiency
- Receptors, Adrenergic, beta-1/genetics
- Receptors, Adrenergic, beta-1/physiology
- Receptors, Adrenergic, beta-2/deficiency
- Receptors, Adrenergic, beta-2/genetics
- Receptors, Adrenergic, beta-2/physiology
- Recombinant Fusion Proteins/physiology
- Sodium/metabolism
- Sodium Channels/metabolism
- Sodium-Potassium-Exchanging ATPase/metabolism
- Specific Pathogen-Free Organisms
- Stroke Volume
- Transduction, Genetic
Collapse
Affiliation(s)
- Gökhan M Mutlu
- Division of Pulmonary and Critical Care Medicine, Northwestern University Feinberg School of Medicine, Chicago, Ill, USA
| | | | | | | | | | | | | | | | | | | | | | | | | |
Collapse
|
9
|
Abstract
Targeted disruption of murine beta-adrenergic receptor (beta-AR) genes has helped to clarify the role of specific beta-AR subtypes in regulating cardiovascular development and function. In the mouse, the beta1-AR is primarily responsible for sympathetic regulation of both cardiac chronotropy and inotropy. In contrast, all three beta-ARs play a role in regulating peripheral vascular tone. The impact of ablation of both beta1- and beta2-ARs on cardiac development and on resting cardiovascular and metabolic parameters is remarkably minimal. However, exercise stress reveals additional important contributions of beta1- and beta2-ARs to cardiovascular performance.
Collapse
MESH Headings
- Animals
- Cardiovascular Physiological Phenomena
- Cardiovascular System/growth & development
- Cardiovascular System/metabolism
- Cardiovascular System/physiopathology
- Exercise/physiology
- Humans
- Mice
- Muscle, Smooth, Vascular/growth & development
- Muscle, Smooth, Vascular/metabolism
- Muscle, Smooth, Vascular/physiopathology
- Myocardial Contraction/drug effects
- Receptors, Adrenergic, beta/physiology
- Receptors, Adrenergic, beta-1/deficiency
- Receptors, Adrenergic, beta-2/deficiency
- Sympathetic Nervous System/growth & development
- Sympathetic Nervous System/metabolism
- Sympathetic Nervous System/physiopathology
Collapse
Affiliation(s)
- Daniel Bernstein
- Department of Pediatrics, Stanford University, Palo Alto, CA, USA.
| |
Collapse
|
10
|
Devic E, Xiang Y, Gould D, Kobilka B. Beta-adrenergic receptor subtype-specific signaling in cardiac myocytes from beta(1) and beta(2) adrenoceptor knockout mice. Mol Pharmacol 2001; 60:577-83. [PMID: 11502890] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/21/2023] Open
Abstract
The sympathetic nervous system modulates cardiac contractility and rate by activating beta-adrenergic receptors (beta AR) expressed on cardiac myocytes and specialized cells in the sinoatrial node and the conduction system. Recent clinical studies have suggested that beta-adrenergic receptors also play a role in cardiac remodeling that occurs in the pathogenesis of cardiomyopathy. Both beta(1) and beta(2) adrenergic receptors are expressed in human and murine hearts. We have examined the effect of beta AR activation on the spontaneous contraction rate of neonatal myocyte cultures from wild-type and beta receptor knockout (KO) mice (beta(1)AR-KO, beta(2)AR-KO and beta(1)beta(2)AR-KO mice). Stimulation of the beta(1)AR in beta(2)AR-KO myocytes produces the greatest increase in contraction rate through a signaling pathway that requires protein kinase A (PKA) activation. In contrast, stimulation of the beta(2)AR in beta(1)AR-KO myocytes results in a biphasic effect on contraction rate with an initial increase in rate that does not require PKA, followed by a decrease in rate that involves coupling to a pertussis toxin sensitive G protein. A small isoproterenol-induced decrease in contraction rate observed in beta(1)beta(2)AR-KO myocytes can be attributed to the beta(3)AR. These studies show that all three beta AR subtypes are expressed in neonatal cardiac myocytes, and the beta(1)AR and beta(2)AR couple to distinct signaling pathways.
Collapse
MESH Headings
- Adrenergic beta-Agonists/pharmacology
- Animals
- Cyclic AMP/metabolism
- Cyclic AMP-Dependent Protein Kinases/metabolism
- Heart/drug effects
- Heart/physiology
- Isoproterenol/pharmacology
- Mice
- Mice, Knockout
- Myocardial Contraction/drug effects
- Myocardium/metabolism
- Receptors, Adrenergic, beta-1/deficiency
- Receptors, Adrenergic, beta-1/metabolism
- Receptors, Adrenergic, beta-2/deficiency
- Receptors, Adrenergic, beta-2/metabolism
- Receptors, Adrenergic, beta-3/metabolism
- Signal Transduction/physiology
Collapse
Affiliation(s)
- E Devic
- Howard Hughes Medical Institute, Stanford University Medical School, Stanford, California 94305, USA
| | | | | | | |
Collapse
|
11
|
Zhou YY, Wang SQ, Zhu WZ, Chruscinski A, Kobilka BK, Ziman B, Wang S, Lakatta EG, Cheng H, Xiao RP. Culture and adenoviral infection of adult mouse cardiac myocytes: methods for cellular genetic physiology. Am J Physiol Heart Circ Physiol 2000; 279:H429-36. [PMID: 10899083 DOI: 10.1152/ajpheart.2000.279.1.h429] [Citation(s) in RCA: 220] [Impact Index Per Article: 9.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Rapid development of transgenic and gene-targeted mice and acute genetic manipulation via gene transfer vector systems have provided powerful tools for cardiovascular research. To facilitate the phenotyping of genetically engineered murine models at the cellular and subcellular levels and to implement acute gene transfer techniques in single mouse cardiomyocytes, we have modified and improved current enzymatic methods to isolate a high yield of high-quality adult mouse myocytes (5.3 +/- 0.5 x 10(5) cells/left ventricle, 83.8 +/- 2.5% rod shaped). We have also developed a technique to culture these isolated myocytes while maintaining their morphological integrity for 2-3 days. The high percentage of viable myocytes after 1 day in culture (72.5 +/- 2.3%) permitted both physiological and biochemical characterization. The major functional aspects of these cells, including excitation-contraction coupling and receptor-mediated signaling, remained intact, but the contraction kinetics were significantly slowed. Furthermore, gene delivery via recombinant adenoviral infection was highly efficient and reproducible. In adult beta(1)/beta(2)-adrenergic receptor (AR) double-knockout mouse myocytes, adenovirus-directed expression of either beta(1)- or beta(2)-AR, which occurred in 100% of cells, rescued the functional response to beta-AR agonist stimulation. These techniques will permit novel experimental settings for cellular genetic physiology.
Collapse
MESH Headings
- Adenoviridae
- Animals
- Calcium/metabolism
- Cell Culture Techniques/methods
- Cell Membrane/physiology
- Cells, Cultured
- Female
- Gene Transfer Techniques
- Heart Ventricles
- Male
- Mice
- Mice, Inbred C57BL
- Mice, Inbred DBA
- Mice, Inbred Strains
- Mice, Knockout
- Myocardium/cytology
- Myocardium/metabolism
- Receptors, Adrenergic, beta-1/deficiency
- Receptors, Adrenergic, beta-1/genetics
- Receptors, Adrenergic, beta-1/physiology
- Receptors, Adrenergic, beta-2/deficiency
- Receptors, Adrenergic, beta-2/genetics
- Receptors, Adrenergic, beta-2/physiology
- Transfection/methods
Collapse
Affiliation(s)
- Y Y Zhou
- Laboratory of Cardiovascular Science, Gerontology Research Center, National Institute on Aging, National Institutes of Health, Baltimore, Maryland 21224, USA
| | | | | | | | | | | | | | | | | | | |
Collapse
|
12
|
Rohrer DK, Chruscinski A, Schauble EH, Bernstein D, Kobilka BK. Cardiovascular and metabolic alterations in mice lacking both beta1- and beta2-adrenergic receptors. J Biol Chem 1999; 274:16701-8. [PMID: 10358009 DOI: 10.1074/jbc.274.24.16701] [Citation(s) in RCA: 221] [Impact Index Per Article: 8.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
The activation state of beta-adrenergic receptors (beta-ARs) in vivo is an important determinant of hemodynamic status, cardiac performance, and metabolic rate. In order to achieve homeostasis in vivo, the cellular signals generated by beta-AR activation are integrated with signals from a number of other distinct receptors and signaling pathways. We have utilized genetic knockout models to test directly the role of beta1- and/or beta2-AR expression on these homeostatic control mechanisms. Despite total absence of beta1- and beta2-ARs, the predominant cardiovascular beta-adrenergic subtypes, basal heart rate, blood pressure, and metabolic rate do not differ from wild type controls. However, stimulation of beta-AR function by beta-AR agonists or exercise reveals significant impairments in chronotropic range, vascular reactivity, and metabolic rate. Surprisingly, the blunted chronotropic and metabolic response to exercise seen in beta1/beta2-AR double knockouts fails to impact maximal exercise capacity. Integrating the results from single beta1- and beta2-AR knockouts as well as the beta1-/beta2-AR double knock-out suggest that in the mouse, beta-AR stimulation of cardiac inotropy and chronotropy is mediated almost exclusively by the beta1-AR, whereas vascular relaxation and metabolic rate are controlled by all three beta-ARs (beta1-, beta2-, and beta3-AR). Compensatory alterations in cardiac muscarinic receptor density and vascular beta3-AR responsiveness are also observed in beta1-/beta2-AR double knockouts. In addition to its ability to define beta-AR subtype-specific functions, this genetic approach is also useful in identifying adaptive alterations that serve to maintain critical physiological setpoints such as heart rate, blood pressure, and metabolic rate when cellular signaling mechanisms are perturbed.
Collapse
Affiliation(s)
- D K Rohrer
- Department of Molecular Pharmacology, Roche Bioscience, Palo Alto, California 94304, USA
| | | | | | | | | |
Collapse
|
13
|
Rohrer DK, Bernstein D, Chruscinski A, Desai KH, Schauble E, Kobilka BK. The developmental and physiological consequences of disrupting genes encoding beta 1 and beta 2 adrenoceptors. Adv Pharmacol 1997; 42:499-501. [PMID: 9327949 DOI: 10.1016/s1054-3589(08)60798-x] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
MESH Headings
- Adrenergic beta-Antagonists/metabolism
- Adrenergic beta-Antagonists/pharmacology
- Animals
- Crosses, Genetic
- Homozygote
- Imidazoles/pharmacology
- Mice
- Mice, Inbred C57BL
- Mice, Inbred DBA
- Mice, Knockout
- Pindolol/analogs & derivatives
- Pindolol/metabolism
- Receptors, Adrenergic, beta-1/deficiency
- Receptors, Adrenergic, beta-1/genetics
- Receptors, Adrenergic, beta-1/physiology
- Receptors, Adrenergic, beta-2/deficiency
- Receptors, Adrenergic, beta-2/genetics
- Receptors, Adrenergic, beta-2/physiology
- Stem Cells
Collapse
Affiliation(s)
- D K Rohrer
- Department of Pediatrics, Stanford University, California 94305, USA
| | | | | | | | | | | |
Collapse
|